The present situation and the future estimation of the hybrid population of Taiwanese macaques near Wakayama city, Japan

Abstract

A population of Taiwanese (or Formosan rock) macaques (Macaca cyclopis) either escaped or was released around 1950 from a zoo in the Ooike area of Wakayama city. The population has increased in size, and some interbreeding with male Japanese macaques (Macaca fuscata) has occurred. This presentation shows the current population size, annual growth rate of the population and the future population size as estimated from analysis of the population census data of 1999 and 2002 and capture data from 2002, 2003 and 2004.
[Results] The estimated population size was about 200 in 1999 and 239-250 in 2002. The numbers of captured and eliminated were 53 in 2002, 146 in 2003 and 43 in 2004. The annual population growth rate is estimated as between 13-15% based on the population census data. The present population size is estimated as between 92-107, but, based on the above growth rate, it will double within 5.2 years if left undisturbed.